Micrometer-indicator



(No Model.) r

' JLBATH.

I r MIOROMETBR INDIGATOR.

. No. 526,960. Patenfse dOo t. 2,1894. P

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NITED S AT S PAT NT f F-Ic-E.

JOHN BATH, OF HYDE PARK, MASSACHUSETTS- MICROMETEFt-INDICATOR.

SPECIFICATION forming part of Letters Patent No. 526,960,1dated Qctober 2, 1894-.

Application filed May 2, 189A- Serial No. 509,789. (No model.) l I To all whom it may concern.-

Be it known that I, JOHN BATH, of Hyde Park, in the county of Norfolk and State of Massachusetts, have invented a new and useful Improvement in Micrometer-Indicators,

which will, in connection with the accompanying drawings, be hereinafter fully. described, and specifically defined in the ap-, pended claims.

my application filed June-10, 1893, Serial No. 477,157, and allowedDecemberZO, 1893, and consists chiefly in 'pivotally attaching the llldl. eating mechanism to the shank by which the tool is held in the tool-.post'of alathe, and in improvements of details of construction, all as hereinafter fully described and pointed out in the appended claims.

In the drawings: Figure l-is a side elevation of my improved indicator with the face plate removed to show the interior construction,- and showing the detached central piece in section. Fig. 2 is a top view of the indicator. Fig. 3 is a sectional top view taken as on line 3-3, Fig. 1, showing the construction of the joint which connects the shank and head. Fig. 4 is a'perspective view of the split ring or bushing which surrounds the hub on the indicator head. Fig. 5 is a section taken as on line 5-5, Fig. 1, and viewed from above said line. Figs. 6 and 7 are perspective views of the multiplying levers detached from the head. Fig. 8 is a top view of the scale of the indicator showing the finer subdivisions'of the scale. Fig. 9 is an elevation of the face plate removed from Fig. 1.

The indicating mechanism consists of a hollow case A; two multiplying levers B and O, lever B being pivoted at D, and lever O at E, the latter carrying a pin F which projects inward and bears against the long arm of lever B near its end as shown. There is a groove in the front edge of the upper and thicker portion of case A inwhich a block G is fitted to slide, and the inner end of which is tapered to a thin edge which bears against the short arm B of lever B, While its outer end is reduced and threaded to receive the con- 50 tact piece H, as shown. A small retaining pin I secured in case A projects into the My present invention is an improvementupon the micrometer indicator described in groove and into a larger hole inblock G and serves to prevent the block from slipping out of the groove endwise when the tool' is tipped so astoffavor suchfla movement. The short arm 0'. of lever. .O istwisted. to present its broad face to aspring. .T which is deposited in a recess in the ease and is compressed betweenv the wall ofthe case and said twisted arm. On the top of-.the 'case is anarched 6o measuring scale K over ,which sweeps .a pointer L attached to lever O. This scale is divided into tenths of an inch, each of'said divisions representing a movement. of one thousandth of an inch of block G and its contact piece H, which is thusregistered on the scale by said multiplying levers, and the scale. may be subdivided into fiftieths of an inch as represented. in "Fig. '8', and thus legibly register with the poiute'r.-and clearly in- 'dicatea movement of the contactpiece ofone- 'fifth;of one-thousandth of an inch.

When the contact piece H is caused to bear against a piece of work which is revolving in a lathe, if the irregularity of the work imparts a movement to the piece H and its sliding block G, the block will impart that movement to lever B, and through it to lever'C, thus multiplying the movement along the scale K one hundred times, the lovers being proportioned to give that result. It is not deemed necessary to explain further in detail the operations and uses of the device which is so well known and understood.

' The indicating mechanism above described is pivotally attached to a shank M which serves to hold the indicator-in the tool-post of a lathe, and, by its capability of being turned on its pivotal connection, to present its contact piece to the work to be tested 0 thereby at varying heights and angles, without change ofposition of the shank, and to get under such conditions a proper registration and indication of the extent of the variations in the work on scale K. For'the pur- 5 pose of making such a connection with'thev shank, a hub N is formed on the back side of case A, as clearly shown in Fig. 3. When the shank and indicator are jointedtogether this hub extends through a hole in the shank. The hole is larger than the hub to receive a bushing P. 7 Shown in Fig. 4. This bushing is open on one sideso-that it maybe compressed upon the hub by means of ascr'ewR threzaded" intothe end of the shank so as to reach a cavity P in the bushing, and thus to act against the elastic bushing to tighten it upon the hub and by its frictional contact therewith to prevent the indicatow'fronr being" "turned relatively to the shank by pressure upon the contact piece whenwoperating the multiplying levers, the friction thus secured between the hub and bushing being always sufficient to resist the tendency of the in di cator to turn in the shank in this actuating the levers when its contact"-piece" is I pressed against the work, in whatever position the indicator "ma Y be relatively to the shankz The parts are secured'together by means of a bread-he'ade'd sorew- S, threaded "into *the 11111; with itshead "bearing against the shank ou thei sideopposite'theindicator,as'shown'i By thus jointing theindicatingmechanism to :the

shank;*I anr en'abled to convenientlyibring the contact point'ofthe indicator into contact" with 'a pie'ce of-workvin a lathe-which may be opposite,' or above", orbe'low', the shank with outraising or lowering the latter; by simply: turning :the indicator about the axis ot its 4 hub. This 1 greatly facilitates the-use ofi the tool and broadensits practical application. The numbe'ring ofthe"scale from the cenfl ter' :is for: convenienceg so that the toolmay be applied to thework in such 'wnanner as to: givethe pointer -free'- play=both= ways;-*and its movement be read =bn =the scale both ways: 1 In some cases the movement'one way will indicate the true variation of thdworkg-in ter takentogetherindicate the true variation, according to the 'appli'catio'n of *th'e-tool I claim-- An indicating mechanism consisting of a hollow case A; a block Gfitted to slide ina groove I in the upper end of the case, and cadapted to carry-a detachable contact piece H on its outer end and to bear against a lev er'atits innenend, and secured with a retaining pin I; "a lever B pivoted in the upper .endof the case; a lever O pivoted in the lower end-of the case,-the two levers being arranged to cross andaot upon each other as described; eb spli-iiag-tl depositedin a recess in the case andarranged to bear at one end against the wall of the case andrat the other'endagainst'I theshort arm' of lever G; and-anarched scale K arranged on the top of the case'andadapted to i register withi-a pointer carriedonthe" long armof-ievenO; all as aud tor the purposes specifieda- 2. Anindicatingmechanism comprising a systemof multiplyingleversya contact=s1ide through which said levers are moved'ya scale on #which such *movement *is indicated and n1easured;'-and*a shankto whichsuch indiw cating' mechanism: is epiv otally' :attached;- all:*-

substantially asspecified 3. In combinatioug case 'A; leversB'and-G -arrangeditherein 'asidescribedwlide G; spring 1 'J; scale -K; hub NyelasticbushingP; screw it; -shank M; and screw- S; *allv substantially as and-"for the purposes specified. J JOHN BATH:

' Wi'tnessesr others the movements both" ways of thecen- EUGENE HUMPHREY. 

